Growing questions
The questions growers ask most, with an honest answer and the gear that goes with it. Can’t find yours? Ask below.
- Ventilation & odour Do I need a fan inside the grow tent as well? Yes. A small oscillating fan keeps the air moving between the leaves, strengthens stems and stops damp pockets. Read the answer →
- Ventilation & odour How do I make my grow tent fan quieter? Turn it down with a speed controller, hang it so it doesn't touch anything, and keep the ducting straight. Read the answer →
- Ventilation & odour How long does a carbon filter last, and when do I replace it? Manufacturers commonly quote about one to two years, but replace it when you smell odour again, whatever the calendar says. Read the answer →
- Ventilation & odour How do I get rid of grow tent smell? Run the exhaust through a properly sized carbon filter and keep the tent under slight negative pressure with no leaks. Read the answer →
- Ventilation & odour Where should the air intake and exhaust go in a grow tent? Exhaust at the top, where the hot air collects. Intake low, ideally on the opposite side, so fresh air sweeps across the plants. Read the answer →
- Ventilation & odour Do I need a speed controller for my exhaust fan? Yes, I'd get one. A fan at full speed is usually louder and pulls more air than the tent needs. Read the answer →
- Ventilation & odour Do I need an inline fan, or is a clip fan enough? You need both. The inline fan swaps the air in the tent, the clip fan only stirs the air that is already there. Read the answer →
- Ventilation & odour What is the best ventilation setup for a 1 x 1 m grow tent? An inline fan of roughly 150 to 250 m³/h pulling through a matching carbon filter, some ducting, and one small clip fan inside. Read the answer →
- Ventilation & odour How do I pick the right carbon filter for my tent? Match the flange diameter to your fan (100, 125, 150 or 200 mm) and choose a filter rated at or above the fan's airflow. Read the answer →
- Ventilation & odour What fan size (m³/h or CFM) do I need for my grow tent? Work out the tent volume (width x depth x height in m³) and pick a fan that can move at least that much air per minute, so roughly 170 m³/h for a 1... Read the answer →
- Lighting How long do LED grow lights actually last? Decent LED lamps are rated for roughly 30,000 to 50,000 hours, which at 12 to 18 hours a day works out to roughly 5 to 11 years. Read the answer →
- Lighting Are quantum boards better than other LED grow lights? Not automatically. Quantum boards are efficient, evenly spread and run silent, but a good panel or bar can match them. Judge a lamp on efficiency a... Read the answer →
- Lighting Can I dim my LED grow light, and when should I? Yes, if the driver is dimmable. Dim it for seedlings and cuttings, for hot spells, or to save power. Read the answer →
- Lighting Does light spectrum matter, and what is a full-spectrum LED? It matters somewhat. Full-spectrum LEDs use white diodes that cover the whole visible range, plus red, and are a good choice for the whole life cycle. Read the answer →
- Lighting What is PPFD and why does it matter? PPFD is the amount of light that actually reaches the plants, in µmol/m²/s. It tells you more than watts or lumens. Read the answer →
- Lighting LED or HPS: which grow light is better? LED, for most people with a tent. It's more efficient, makes less heat and the diodes last years. HPS costs less to buy but needs more ventilation ... Read the answer →
- Lighting Which LED grow light suits a 60x120 cm tent? A real draw of about 150-250 W fits a 60x120 cm tent. The Platinum King 200 W is a good match. Read the answer →
- Lighting How many hours of light do plants need in veg and in flower? Photoperiod plants usually get 18 hours on and 6 off in veg, then 12 on and 12 off to flower. Autoflowering plants can stay on 18/6 or up to 20/4 t... Read the answer →
- Lighting How high should I hang my LED above the plants? Follow the manufacturer's chart. For many 200-400 W panels it is roughly 30-60 cm above the canopy, and stronger lamps hang higher. Read the answer →
- Lighting How do I use a grow light correctly? Hang it at the height the manufacturer recommends, plug it into a timer, and raise or lower it as the plants grow. That covers most of it. Read the answer →
- Lighting How does an LED grow light work? A current passes through many small diodes and each one gives off light. Plant LEDs are tuned to the colours that drive photosynthesis, and they tu... Read the answer →
- Lighting How many lumens does a grow room need per square metre? None, really. Lumens measure what your eye sees. Plants use PPFD, in µmol/m²/s, so compare lamps on that. Read the answer →
- Lighting How many plants can I grow under one LED lamp? It comes down to the lamp's coverage area, not a fixed number. A 300 W LED covers about 80x80 to 90x90 cm in flower, which is room for one to four ... Read the answer →
- Lighting How many watts of LED do I need per square metre? For flowering, plan on roughly 250-400 W of real power draw per m². Check what the lamp actually pulls from the wall, not the 'equivalent' HPS numb... Read the answer →
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